Sound-record and production thereof.



V. H. EMERSON. SOUND RECORD AND PRODUCTION THEREOF. APPLICATION FILEDAUG. 2, 1912.

Patented Jan. 13, 1914K.

UNITED VICTOR H. EMERSON, OF NEW YORK, N. Y., ASSIGNOR T0 AMERICANGRA-PHPI'NH COMPANY, 0F BRIDGEPOBI, CONNECTICUT, A CORPORTIN Gl? WESTVlIRGNlCi'lt.

SOUND-RECORD AND PRODUCTION THEREGIF.

Specification of Letters atent.

Patented dan,

application inea august a, 1era. serie-.i no. 712,954.

of the city, county, and State of New York,

(Whose post-oilice address is 102 West Thirty-eighth street, NewYorkcity, New York,) have invented a new and useful llmprovement inSound-Records andProduetion Thereof, which invention is fully set forthin the -following specification.

My invention relates to sound-records having a laterally-undulatingrecord-groove of substantially uniform depth, commonly known as zigzagrecords.

YThe object ofthe invention is to produce a record of'this type whichwill have improved acoustical qualities. Such zigzag records arecommonly manufactured as disks with the record-groove arranged 'spirallythereon, but they may also be made as cylinders carrying therecord-groove in a helical line around the cylinder; yet, forconvenience of consideration, such recordgroove may be regarded ascontinuing in a straightline, with the lateral undulations on eitherside.

The underlying thought of my inventionA is to provide a (zigzag)record-groove of such character as to produce a duplication or immediaterepetition of each impulse imparted to the reproducing-stylus, so thattheoretically there should be expected a sort of echo as it were; yet inactual practice no echo will be observed by the listener, but merelyincreased 'fullness or roundness of tone. This duplication or repetitionis accomplished by making the original record by means ot arecording-stylus having its two oppdsitely-extending recording-edgesdisposed diagonally with respect to the direction of travel of therecord-groove (instead of transversely thereof as heretofore). AS theresult of this arrangement one record.- ing-edge is slightly advancediii liront of the other, and each concavity produced in one slide-wallof the record-groove will have its complementary (andsimultaneouslyproduced) convexity located diagonally therefrom in theopposite wall of the groove (instead of directly across therefrom).

My invention, then, consists broadly in providing a diagonally-disposedpair or' oppositely-acing recording-edges for making the originalsound-groove; further, in the simultaneous production of diagonally-disposed and complementary leoncavities and convexities corresponding tosound-waves; and also in a sound-record having such diagonal arrangementof its complementary concavities and conveaities.

My invention will be best understood by reference to the annexeddrawings, whichA are on a greatly exaggerated scale, to illus trate thesame diagrammatically.

In these drawings: Figure l represents conyentionally a plan of aportion of a llat reeord-tablet having an ordinary zigzag record-groove,and indicating in cross-eection an ordinary recording-stylus. .fl is asimilar View, indicating my' new record groove,.and indicating incross-section my new recording-stylus; and Fig. 3 is a horizontalsection, on a still larger scale, of my stylus.

Referring to Fig. l, 20 indicates a portion of a flat tablet such asused for making origin nal recordings. 2i indicates a. portion of an-ordinary zigzag record-groove already produced therein, and 22 aportion not yet recorded, Q3 and 2e denoting the side-walls thereof. 25represents the usual recordingstylus, showing in horizontalcross-section, and having its two recordingedges 26 and 27 directlyopposite each other across the record-g1'oove,-the line 2li-2T beingalso the direction vof vibration o'f this laterallyvibratory stylus 25.llt will be noted that each eonvexity a, b, c, etc., has itscorresponding and complementary' concavit Y a", b, c', etc., locateddirectly opposite.

Referring new to Fig. 2, it will be noted that my new recordingstylus 30has its twc oppesitelydlacing recording-edges 3l and 32 arrangeddiagonally ot the record-groove in the tablet that the two members oteach pair of complexnentary concavities and convexities, as ctw-nz?, frwat", etc..l lie diagonally across the recoit groove from each other,instead ot directly opposite each other and that the respective,convexities in one side-wall are slightly in advance ol thecorresponding and complementary eoncavities in the other wall thereof.

ln Fig. 3, my new recording-stylus 3() is shown on a much larger scale.lhe di agonal line 'lO-4:0 contains the recordingidges, while thetransverse lines lll and -11 indicate the direction oit vibration olfthe recording-stylus as a whole. From this it will be seen that myrecording-stylus is pi ruled with two oppos1te1yfacing recording-edgesdisposed in a line diagonal to the direction of vibration of therecording-stylus itself.

Having vthus described my invention, I claim:

LA soundrecord consisting of a taloletv .ing lateral irregularitiescorresponding to sound-Waves, each eoncavity thereof being 'diagonallyopposite its corresponding and complementary conve'xity.

3. A sound record tablet. having a recordgroove of substantially uniformdepth having in one wall lateral undulations corre spending tosound-Waves, and having in the other wall .reverse undulationscorresponding to the same sound-wives, the first named set ofundulations being uniformly in ad- Vance of the correspondingundulations in the other wall.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

VICTOR H. EMERSON.

H. VVATERSON, HENRY WA'rnnsoN, J r.

